Heat oven to 350 degrees. Beat butter and sugars until creamy. Add egg and vanilla and beat well. Combine flour, baking soda, cinnamon and salt and mix together. Add oats, raisins, nuts and any other mix-ins and stir to combine. {They may seem a bit crumbly, but I used a tight little scooper to keep them together. Don't worry, they finish up rich and tender.} Bake on parchment lined baking sheets for 11 minutes. Makes about 2 dozen cookies, depending on size.